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Donkey milk research · Study 153
Donkey milk whey proteins: heat, ultrasound and UV compared
After high-temperature long-time heating, only 23% of lysozyme activity remained in whey proteins from donkey milk; lactoferrin decreased by 70% and immunoglobulin G by 77%. According to the authors, non-thermal methods such as ultrasound and UV treatment preserved these components better and mainly altered particle size, turbidity and sulphur groups of the proteins.
At a glance · tap the cards
The key figures
Study design
How it was studied
Laboratory study by a research group at Qilu University of Technology in Jinan (China): whey proteins from donkey milk were treated thermally (including high-temperature long-time heating) and non-thermally with ultrasound and UV light. Fluorescence, particle size, turbidity, free sulfhydryl groups, foaming and emulsion stability as well as lysozyme activity and lactoferrin and IgG contents were measured. Assessment based on the abstract: the full text was not available to the editorial team, so temperatures, treatment times, sample numbers and milk origin are unknown.
Results
What the study measured
Without heat treatment, the whey proteins showed notable stability according to the abstract; excessive heating, by contrast, markedly altered their structure and functional properties.
After high-temperature long-time heating, fluorescence intensity and foaming and emulsion stability decreased. 23% of lysozyme activity was retained; lactoferrin decreased by 70%, IgG by 77%.
According to the authors, non-thermal methods preserved the active components of the whey proteins better than heat treatment. The abstract gives no figures for this.
Ultrasound reduced particle size and turbidity. UV light oxidised disulphide bonds in the protein and increased free sulfhydryl groups, which the authors link to better foaming and emulsion stability.
Authors’ conclusion: The study offers a scientific basis for processing and applying donkey milk whey proteins and can help in developing dairy products tailored to specific health functions. What it does not show: protein structure and activity were measured in the lab; it says nothing about any health significance of heated or unheated donkey milk.
Critical appraisal
Strengths and limitations
Isolated whey proteinsClear limitation
Whey proteins were treated, not whole donkey milk. In milk, fat, casein and minerals can influence behaviour under heat.
Conditions unknownNote
Temperatures, times, ultrasound and UV doses are only in the full text. Whether the conditions reflect practice cannot be judged.
Outlook beyond the dataClear limitation
The reference to products with health functions is the authors’ perspective. No effects were measured.
Only the abstract assessedNote
Sample numbers, replicates and the values for ultrasound and UV are missing. Only the three percentages for heat treatment are known.
Direct comparison of methodsStrength
Thermal and non-thermal treatments were compared on the same whey proteins with the same measures, with concrete figures for three heat-sensitive components.
Editorial note: The paper provides concrete lab values on how strongly long high-temperature heating alters lysozyme, lactoferrin and IgG in donkey milk whey proteins. This is a technological finding on processing. No conclusion on health differences between heated and unheated donkey milk can be drawn from it. To the research archive.
Research question for DON DONKEY’S®
How much lysozyme activity, lactoferrin and IgG does our frozen donkey milk contain after thawing compared with fresh milk – and how much of it is retained in donkey milk powder?
Original publication
Effect of thermal and nonthermal processing methods on the structural and functional properties of whey protein from donkey milk
Original title: Effect of thermal and nonthermal processing methods on the structural and functional properties of whey protein from donkey milk
Ma M., Luo J., Wang X., Wang N., Wang C., Liu G., Jiang H., Zhang X., Yuan C.
Journal of Dairy Science · 2024 · 107(12), 10439–10451
College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China (according to author information)
Transparency: according to the database entry, funded by the Shandong Province Natural Science Foundation and the Shenzhen Municipal Fundamental Research Program. Conflicts of interest could not be checked from the abstract. No product-related statement for DON DONKEY’S®.
Summarised and checked by the DON DONKEY’S editorial team against the original publication · As of: November 2026
The study summarised above was carried out independently of DON DONKEY’S® and does not relate to our products. It serves solely to inform about the state of research.
DON DONKEY’S® donkey milk and donkey milk powder are foods. They are not intended to prevent, treat or cure any disease and do not replace medical advice.
From our shop
DON DONKEY’S® donkey milk
100 % donkey milk · raw milk, frozen
On this page we report the findings of a published study. Independently of that, you will find our donkey milk here: 100 % donkey milk, frozen as raw milk.
100 ml bottle / 100ml · Unit price: €249,00 / 1 l · incl. VAT, plus shipping
Also in our shop
Donkey Milk Powder
Donkey milk in powder form
For anyone who prefers a longer shelf life: our donkey milk in powder form – easy to store and portion.
20g · Unit price: €1.245,00 / 1 kg · incl. VAT, plus shipping